Engineering:BMW Type 255

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BMW Type 255 Kompressor
BMW RS 500 Kompr, Bj. 1939.JPG
ManufacturerBMW Motorrad
Also calledType 255 RS 500
Production1935–1939[1]
PredecessorBMW WR 750
ClassStreet racing
Engine492 cc DOHC supercharged boxer twin with aluminium cylinders; magnesium engine block and supercharger casing[2]
Fuel: gasoline-oil mix
Bore / stroke66×72 mm[1]
Top speedc. 220 km/h (140 mph)[2]
Power60 hp (45 kW)[2]
Transmission4-speed, shaft drive[1]
Frame typeTubular steel twin cradle
SuspensionFront: Oil-filled telescopic forks
Rear: Rigid (1935–1936) Plunger (after 1936)[1]
Weight138 kg (304 lb)[2] (wet)
Georg Meier riding the 1939 BMW Type 255 Kompressor at the 1989 Isle of Man TT Race
Supercharger-engine-gearbox unit construction assembly

BMW Type 255 Kompressor (also known as the 500 Kompressor, RS 255, RS255 and Type 255 RS 500) was a supercharged boxer twin race motorcycle from the 1930s. A BMW 255 Kompressor was ridden to victory by Georg Meier in the 1939 Isle of Man TT and the first win by a non-British competitor in the premier 500cc Senior TT class.[3] A similar BMW 255 Kompressor machine was auctioned in 2013 for US$480,000, the second-highest price ever paid at auction for a motorcycle.[4][5][6]

Supercharger

A Zoller sliding vane supercharger is bolted to the front of the DOHC engine, driven directly by the crankshaft, and is lubricated by castor oil added to the fuel.[1][2][7] It provided c. 15 psi (100 kPa).[1]

Records

The machine set a number of race records, including the first lap over 100 miles per hour (160 km/h) at a major event, when Georg Meier won the Belgian motorcycle Grand Prix in 1939, and Ernst Jakob Henne's capture of the motorcycle land-speed record in 1936 on a model with a streamlined fairing.[1]

Today

An example is on display at the BMW Museum in Munich.[8]

Further reading

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Falloon, Ian (2003), The BMW Story: Production and Racing Motorcycles From 1923 to the Present Day, Haynes, pp. 24–26, ISBN 185960854X 
  2. 2.0 2.1 2.2 2.3 2.4 BMW News: A TT blast from the past, BMW Motorrad, April 5, 2013, http://www.bmw-motorrad.com/com/en/individual/news/2011/news.jsp?id=2187, retrieved September 10, 2014 
  3. The Nazi TT – Hitler's 1939 Propaganda Victory in the Isle of Man page 73-80 by Roger Willis Motobusiness (2009) Quine & Cubbon Ltd ISBN:978-0-9562457-0-0
  4. "BMW brings together past and present on the Isle of Man", New Zealand Herald, August 22, 2014, http://m.nzherald.co.nz/motoring/news/article.cfm?c_id=9&objectid=11312233 
  5. "Bikes sold at auction:1939 BMW RS 255 Kompressor", Hindustan Times, April 4, 2014, http://www.hindustantimes.com/photos-news/Haryana/bikessoldatauction/Article4-1204135.aspx 
  6. d'Orléans, Paul (May 18, 2014), "Top 20 most expensive motorcycles at auction", The Vintagent, http://thevintagent.blogspot.com/2010/11/top-20-at-auction-updated.html 
  7. Williams, Greg (September–October 2012), "The BMW RS 255 Kompressor: Making History Going Fast", Motorcycle Classics, http://www.motorcycleclassics.com/classic-german-motorcycles/bmw-rs-255-kompressor-zmwz12sozbea.aspx 
  8. d'Orléans, Paul (December 28, 2008), "New BMW Museum, Munich", The Vintagent, http://thevintagent.blogspot.com/2008/12/new-bmw-museum-munich.html 

External links